Ethyl bromoacetate → (3S,4S)-3-azido-4-ethoxycarbonylmethoxy-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

96.1 A suspension of 210 mg NaH (55% in mineral oil) in 3 ml DMF was treated at 0° C. with 1.0 g (3S,4S)-3-azido-4-hydroxy-pyrrolidine-1-carboxylic acid tert-butyl ester in 6 ml DMF. The reaction mixture was stirred at 0° C. for 90 min, then it was cooled to 0° C. A solution of 0.53 ml ethyl bromoacetate was added dropwise. The reaction mixture was slowly warmed to r.t., stirred overnight, then heated for 1 hr at 50° C. After cooling to r.t. the mixture was taken up in EtOAc and washed with H2O. The combined organics were dried over MgSO4, filtrated and concentrated. The crude product was purified by column chromatography (silica gel; cyclohexane->cyclohexane/EtOAc 3:2) to give 584 mg (3S,4S)-3-azido-4-ethoxycarbonylmethoxy-pyrrolidine-1-carboxylic acid tert-butyl ester as yellow liquid. MS 315.2 ([M+H]+)

Provenance & Evidence